8‐Hydroxylated derivatives of diazabicyclo[4.3.0]nonanes, 2,5‐dioxodiazabicyclo[4.3.0]nonanes and some related esters

Pharmacological considerations prompted the authors to synthesize a series of 8‐hydroxylated optically active derivatives of diazabicyclo[4.3.0]nonanes and of their 2,5‐dioxo analogs from trans‐4‐hydroxy‐L‐proline. Esterification with appropriate anhydrides led to the corresponding esters with 6S,8R configuration. Inversion of configuration at C‐8 was performed using Mitsunobu method and led to the diastereoisomeric series of 6S,8S esters. A tentative pharmacological evaluation was carried out in the area of sedative and spasmolytic activities.